The drift trajectory of giant iceberg C-7 traversing the Weddell Sea for more than 2-years wassuccessfully simulated. Application of the "classical" driving forces like wind and ocean currentsresulted in a significant discrepancy between modeled and observed iceberg velocities in thewestern Weddell Sea. The most realistic drift pattern in space and time was achieved by addinga sea ice force which represents the ability of a dense sea ice cover (>90%) to lock in icebergsand collect the momentum of the wind over a vast area. This process was parameterized using asea ice strength 'P' which depends on sea ice concentration and thickness, both having highestvalues in winter and in the perennial covered western Weddell Sea. As a consequence of thesensitivity to sea ice the timing of the iceberg drift becomes important, revealing the region offBrunt Ice Shelf (eastern Weddell Sea) as a location where bergs either continue westward withthe coastal current or follow a southern branch onto the shallow continental shelf.